Pin clamp with multi-thickness clamping feature

ABSTRACT

A pin clamp for clamping a workpiece includes a housing having a longitudinal axis and a locating pin extending through the housing. The locating pin is sized to be positioned within an opening of the workpiece. A finger is positioned adjacent to the locating pin and movable in a transverse direction relative to the longitudinal axis to retain the workpiece on the locating pin. An exterior driving linkage is configured to move the locating pin in opposite directions along the longitudinal axis. A locking arrangement is carried by the housing. A sequence cam is connected with the exterior driving linkage thereby allowing axial movement of the exterior driving linkage to be converted into transverse movement of the sequence cam. The sequence cam includes an engagement surface which engages the locking arrangement to lock the locating pin and the finger against the workpiece upon retraction of the exterior driving linkage.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.13/653,803, entitled “PIN CLAMP WITH MULTI-THICKNESS CLAMPING FEATURE”,filed Oct. 17, 2012, which is a non-provisional of U.S. ProvisionalApplication Ser. No. 61/548,448, entitled “PIN CLAMP WITHMULTI-THICKNESS CLAMPING FEATURE”, filed Oct. 18, 2011, which isincorporated herein by reference. This is further a non-provisionalapplication based upon U.S. provisional patent application Ser. No.62/149,319, filed Apr. 17, 2015, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to pin clamp assemblies.

2. Description of the Related Art

Pin clamps are typically used for gripping onto sheets of metal, oftenon automobile assembly lines so some process can be performed on thatsheet metal. The pin clamp includes a locating pin that is extendablethrough a hole in the sheet metal. A finger extends from the locatingpin which then retracts so the finger clamps down onto the sheet.Examples of pin clamps can be found in U.S. Pat. Nos. 7,182,326,7,516,948, 7,448,607, 7,815,176, and 7,467,788.

In today's automobile manufacturing environment, however, someautomobiles may be manufactured in multiple configurations. For example,an automobile may be manufactured in a first configuration that employsan internal combustion engine. That same automobile may also be offeredin a second configuration that employs a battery powered motor. In theseinstances, it might be necessary for that automobile to have a differentframe depending on whether it is gas or electric powered. An electricpowered automobile requires a stronger frame to hold the substantialweight of the batteries needed to power it. A different size frame mayrequire a thicker metal. Because it is the same vehicle, however, itotherwise uses many of the same parts. This makes it desirable to usethe same assembly line for both versions, if possible.

Conventional pin clamps are adjusted to clamp down on workpieces ofvaried thicknesses. This is particularly the case for clamps having ahold mechanism that still clamp down on a workpiece even under powerloss (such as pressurized air). These clamps need adjustment toaccommodate this different thickness. Making such adjustments adds timeand expense to the manufacturing process.

SUMMARY OF THE INVENTION

The present invention provides a pin clamp that can hold a car part of afirst thickness, release the clamp from its power supply while it stillholds onto the part, process the part, reattach the power supply to theclamp to release the part, and then start the process again but clampingonto another part having a second thickness. This allows the part to beprocessed anywhere along the assembly line without the clamp having tobe constantly connected to a power source. It also no longer requiresany readjustment of the pin clamp between removing the workpiece offirst thickness and replacing it with a workpiece of second thickness.

The pin clamp of the present invention includes an internal lock thatcompensates for, illustratively, up to about 1.0 millimeters ofvariation in material thickness. A lock holds the finger firm againstthe various material thicknesses. This means that panels of differentthicknesses can be held by the clamp and all will be held firmly with noplay. The pin clamp of the present invention further includes anexterior driving linkage that allows the pin clamp to be operated usingan external mechanism.

The invention in one form is directed to a pin clamp for clamping aworkpiece. The pin clamp has a housing with a longitudinal axis and alocating pin extending through the housing. The locating pin is sized tobe positioned within an opening of the workpiece. A finger isselectively radially extendable from and retractable into the locatingpin in a transverse direction relative to the longitudinal axis toretain the workpiece on the locating pin. An exterior driving linkage isconfigured to move the locating pin in opposite directions along thelongitudinal axis. A sequence bracket is attached to the housing. A lockbracket attached to the housing opposite the sequence bracket. Asequence cam is connected with the exterior driving linkage in a mannerallowing axial movement of the exterior driving linkage to be convertedinto transverse movement of the sequence cam perpendicular to thelongitudinal axis. The sequence cam includes a ledge configured to ridealong a top surface of the sequence bracket during a first part of aclamping sequence. The sequence cam further includes an engagementsurface which engages an angled surface of the lock bracket during asecond part of the clamping sequence to lock the locating pin and thefinger against the workpiece upon retraction of the exterior drivinglinkage.

An advantage of the present invention is that it can be operated usingan external mechanism while retaining the ability to remain clampedwithout constant application of input force. The pin clamp of thepresent invention is again capable of compensating for variations inwork material thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a perspective view of an embodiment of a pin clamp of thepresent invention;

FIG. 2 is an exploded perspective view of the pin clamp shown in FIG. 1;

FIG. 3 is another perspective view of the pin clamp shown in FIGS. 1 and2, with part of the housing removed;

FIGS. 4a and 4b are side and end views, respectively of the pin clampshown in FIGS. 1-3;

FIG. 5-12 are side views illustrating a sequence of operation of the pinclamp of the present invention;

FIGS. 13 and 14 are side views illustrating locking of the pin clamp ofthe present invention;

FIG. 15 is an exploded perspective view of a cover, Z bracket andsequence cam;

FIG. 16 is a top sectional view showing how the spring loaded Z bracketbiases the sequence cam toward the lock bracket;

FIGS. 17a and 17b are side and side sectional views, respectively,illustrating details of a linear actuator in the form of a piston andcylinder arrangement;

FIG. 18 is a side view of an additional embodiment of the presentinvention;

FIG. 19 is a side view of an additional embodiment of the presentinvention;

FIG. 20 is a side view of an additional embodiment of the presentinvention;

FIG. 21 is a side view of an additional embodiment of the presentinvention;

FIG. 22 is an isometric cutaway view of an additional embodiment of thepresent invention; and

FIG. 23 is an isometric cutaway view of an additional embodiment of thepresent invention.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates an embodiment of the invention, in one form, and suchexemplification is not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIG. 1, there isshown a pin clamp 2 which includes a housing 4 with a locating pin 6extending therefrom. A collar 8 illustratively surrounds locating pin 6.A finger 10 is selectively radially extendable from and retractable intothe locating pin. A cover 12 attaches to housing 4 via fasteners 14.This allows access to the internal components of clamp 2 as needed. Alinear actuator in the form of a pneumatic actuator 16 extends fromhousing 4 illustratively opposite locating pin 6. A portion of pistonrod 122 partially extends from actuator 16 and includes a nut 124illustratively attached to the end thereof. Fasteners 25 illustrativelyattach collar 8 to housing 4.

An exploded view of pin clamp 2 is shown in FIG. 2. This view depictshousing 4 with a cavity 18 formed therein to receive components of pinclamp 2 as further discussed. An opening 26 in housing 4 is configuredto receive locating pin 6.

Illustratively, locating pin 6 is hollow so it may receive drive rod 28.It also includes slots 30 and 32 along with an opening 34 configured toreceive finger 10. Collar 8 is shown with opening 36 configured toreceive a portion of locating pin 6. A ledge 38 may serve as a basesurface for a workpiece in the form of a piece of sheet metal or othermaterial that is intended to be clamped down by finger 10.

Fasteners 25 attach collar 8 to housing 4. A cover plate 40 attaches tohousing 4 via fasteners 42 in order to illustratively cover one side ofcavity 18 opposite cover 12. Rod 44 extends though locating pin 6 andsupports cam roller 57 that travels along the internal cam surface ofcam slot 74 as described further herein. A lock bracket 46 fits intocavity 18 using fastener 47. Similarly, sequence bracket 48 fits intocavity 18 as well and attaches thereto via fastener 49. A Z-bracket 50with tabs 52 and 53, and spring 51 are also located within housing 12and is retained by plate 13. A sequence cam 54, a roller 56 and a post58 are also directed inwardly of cavity 18. Actuator 16 includes apiston rod 60 extending from one end and configured to couple tosequence cam 54 via rod 44 acting through cam roller 57. In thisillustrative embodiment, piston rod 60 is “U” shaped to accommodatesequence cam 54. (See, also, FIG. 17b .) Rod 122 extends from the otherend of actuator 16. Fasteners 62 attach actuator 16 to housing 4.

In the illustrated embodiment, cam roller 57 defines a cam follower thatis positioned within and engages the internal cam surface of slot 74.However, it is possible to use a different type of cam follower. Forexample, rod 44 could itself define a cam follower which rides withinthe cam surface of slot 74.

As previously discussed, pin clamp 2 is configured to first, clamp ontoa material of first thickness under fluid power (such as pressurizedair), then have that power disconnected, still securely hold thematerial as it moves down the assembly line, and then reattach fluidpower to release the material. Then, that same pin clamp, without anyfurther adjustment or modification, is able to clamp down onto amaterial of a second thickness under subsequent fluid power and repeatthe process again. In other words, the pin clamp may hold pieces ofsheet metal or other workpieces of a variety of thicknesses and holdthose workpieces under power loss without any modification to the pinclamp.

In alternative embodiments the power may be electrical or hydraulic.

A perspective isolated view of several of the internal components of pinclamp 2 is shown in FIG. 3. This view depicts the relative positioningof several of the components that help keep the pin clamp locked downonto a workpiece of particular thickness when no fluid pressure is beingapplied to finger 10. As shown herein, cover 12 includes a springbracket 64 configured to hold Z-bracket 50 and a spring 51. Tab 52 isconfigured to push sequence cam 54. Sequence cam 54 extends through slot32 through locating pin 6. Rod 44 and dowel 70 are disposed through slot30. Located on opposite sides of locating pin 6 is lock bracket 46 andsequence bracket 48. Ledge 66 of sequence cam 54 rides along theillustrative top surface of sequence bracket 48 while roller 56 isconfigured to engage angled surface 68 of lock bracket 46. Roller 56defines an engagement surface which locks with angled surface 68. Angledsurface 68 is positioned at an angle of between 0° to 10°, relative to adirection of movement of sequence cam 54, and may be a flat surface orhave a curved or differently shaped surface.

FIG. 3 also shows how piston rod 60 extends up through locating pin 6.The U-shaped channel in piston rod 60 is illustratively configured toallow sequence cam 54 to pass in between without interference. Drive roddowel 70 also extends through slot 30 and is disposed in cam slot 72 ofsequence cam 54. It will be appreciated as further discussed herein thatdowel 70 also connects sequence cam 54 with drive rod 28 so that thepath of cam slot 72 dictates the corresponding movement of drive rod 28which in turn dictates the extension or retraction of finger 10. Rod 44connects piston rod 60 with sequence cam 54 via slot 74 for moving thesame in directions 76 and 78. (See, also, FIG. 4.)

Progression views depicting how pin clamp 2 operates to clamp down andlock onto a workpiece is shown in progression views of FIGS. 4-7. Asshown in FIG. 4a , locating pin 6 is illustratively positioned adistance 80 above collar 8. In this illustrative embodiment, distance 80may be 12.5 millimeters, for example. It is appreciated, however, thatthis distance is illustrative and such distance can be modified asdesired. At this point, ledge 66 of sequence cam 54 is sitting on top oflock bracket 48. It is contemplated that movement of piston rod 60 fromactuator 16 in direction 82 will begin moving sequence cam 54 indirection 78. As shown in FIG. 4b , the upper position of slot 74includes a locking position 86 that prevents roller 57 from moving ifthere is an air pressure loss. Also included is detent 59 which helpsprevent piston rod 60 from dropping out of locking position 86 under aloss of fluid power. Illustratively, sequence cam 54 receives a biasforce in direction 78 from bracket 50. This keeps detent 59 pushingagainst roller 57 regardless of whether air pressure is being applied topiston rod 60. If air pressure is lost, detent 59 of sequence cam 54 isstill pushing against roller 57 preventing it from dislodging fromlocking position 86.

The view in FIG. 5 depicts the consequence of piston rod 60 movingdownward in direction 82. As this happens, roller 57 pulls down out ofthe pin extended position 86. The roller 57 then contacts surface 75 incam slot 74, which causes cam 54 to slide in direction 78. This motioncauses drive rod 28 to move downwards. Cam follower 92 on drive rod 28also moves in direction 82. Cam follower 92 is engaged in cam slot 94,which pushes finger 10 in direction 76, extending finger 10 outward fromlocating pin 6. As sequence cam 54 slides in direction 78, finger 10moves to a fully extended position, just as ledge 66 of sequence cam 54is no longer engaged by sequence bracket 48. Roller 56 is mounted on apin 55 that is connected to sequence cam 54, and moves from cavity 90while approaching lock bracket 46. It is appreciated that theconfiguration and size of cam slot 94 can be modified to create thedesired movement of finger 10 upon response to the drive rod's movement.

The view of clamp 2 in FIG. 6 shows locating pin 6 moving towards itsclamped and locking position. As piston rod 60 moves in direction 82,roller 57 contacts cam surface 98 that is part of cam 74. The resultingforce causes locating pin 6 to move in direction 82, thus narrowing thegap between collar 8 and finger 10. At least a portion of roller 56 islower than lock bracket 46.

The view in FIG. 7a shows locating pin 6 of clamp 2 moved to its finalclamping thickness represented by spacing 100. Illustratively, thespacing maybe 2.5 mm. At this point, a workpiece will be securely heldby finger 10 against collar 8. As piston rod 60 moves downward indirection 82, roller 57 moves down angled surface 98 of cam slot 74.This increasing angle forces sequence cam 54 to continue moving indirection 78 and begin wedging roller 56 up against angled surface 68creating a locking function. Cam slot 72 is shaped so that as sequencecam 54 continues to move in direction 78, the drive rod 28 remainsstationary with respect to locating pin 6, so that the cam follower 92on drive rod 28 does not move within cam slot 94 and so that finger 10does not withdraw. At this point, a loss of air pressure to piston rod60 will not cause finger 10 to release itself from the workpiece. Apractical effect of this is that while clamp 2 holds onto the workpiece,its power source may be disconnected allowing clamp 2 and its workpieceto move to a different location. Despite this, clamp 2 still holds theworkpiece in place while maintaining the clamping force originallyprovided by pneumatic actuator 16.

FIGS. 8 and 9 demonstrate the operation of pin clamp 2 to remove theworkpiece. It should be appreciate, however, that in the illustrativeembodiment, prior to the movement shown in FIGS. 8 and 9, no power isbeing supplied to clamp 2. Pressurized air is not needed to maintain theclamping force until the workpiece is needed to be removed from clamp 2.

As shown in FIGS. 7, 8, and 9, roller 57 moves within cam slot 74 ofsequence cam 54. Cam slot 74 is shaped as such to generate low powerwhen piston rod 60 is moving in direction 82 toward the clampedposition, and high power when moving in direction 84 toward the releaseposition. This may be made necessary by loads introduced due to welds orby weld guns, requiring increased force in the releasing direction. Whenclamping, roller 57 rides along surface 98 which produces a low force.Roller 56 moving along the illustrative 7 degree angle of surface 68generates enough additional downward force to allow the necessarystructures to move. Conversely, when raising piston rod 60 in direction84, roller 57 travels along surface 102 which creates a high force tomove sequence cam 54 back in direction 76 and help remove roller 56 fromunder surface 68.

To remove the workpiece, pressurized air is resupplied to clamp 2 movingpiston rod 60 in direction 84. This moves roller 57 upwards in direction84 as well and against cam surface 102 of cam slot 74. This curved shapeof surface 102 causes sequence cam 54 to move in the opposite direction76. This movement of sequence cam 54 begins to extricate roller 57 fromsurface 68 of lock bracket 46.

The view in FIG. 9 further demonstrates the operation of clamp 2 aspiston rod 60 moves in direction 84. As shown, roller 57 continuesfollowing surface 102 of slot 74 which continues to move sequence cam 54in direction 76. Roller 56 clears surface 68 of locking bracket 46further allowing sequence cam 54 and locating pin 6 to move in direction84. This movement also begins to move pin 70 in slot 72 which will(though not yet) move follower 92 in slot 94 to retract finger 10. Asshown in this view, however, at this point locating pin 6 is what isbeing moved by piston rod 60 to raise finger 10 from the workpiece adistance indicated by reference number 104. Continued movement of pistonrod 60 in direction 84, moves pin 70 into angled section 88 pushingpiston rod 28 upward in direction 84 relative to the locating pin 6.This retracts finger 10 and moves roller 57 up into locking section 86.In other words, clamp 2, as shown in FIG. 9, continues to move asdescribed until the components are in the position as shown in FIG. 4where the process may start all over again.

To that end, the view in FIG. 10 depicts clamp 2 clamping down on aworkpiece that is thinner than the workpiece clamped down onto in FIGS.4-7. In this illustrative embodiment, spacing 106 may illustratively be2 rams instead of 2.5 millimeters, as employed in FIGS. 4-7. In FIG. 10,the sequence of movement is essentially the same as that described inFIGS. 4-7, except now the further clamping distance (for a thinnerworkpiece) means sequence cam 54 will move even further in direction 78which makes roller 56 wedge further along surface 68 of lock bracket 46.No other components to clamp 2 need to be manually adjusted toaccommodate a thinner workpiece. As shown, locating pin 6 is drawnfurther down by piston rod 60 in direction 82 moving sequence cam 54 indirection 78 in similar fashion as that described in FIGS. 4-7. The onlydifference is that the spacing 106 is smaller than spacing 100 in FIG.7. This moves roller 57 further down cam surface 98 which allows pin 70to move further along slot 72 and roller 56 further down surface 68 indirection 78. Compare the relative positioning of rollers 56 and surface68 between FIGS. 7 and 10. This means that when pressurized air isdisconnected from clamp 2, finger 10 and locating pin 6 will still holdthe thinner workpiece in the same manner as that shown in FIG. 7 for athicker workpiece. The views in FIGS. 11 and 12 are similar to that of10 except pin clamp 2 is now clamping onto even thinner workpieces, suchas for the spacing shown in 108 of FIG. 11 and 110 of FIG. 12. It isappreciated that spacing 110 is thinner than spacing 108 which is itselfthinner than spacing 106. To accomplish this, sequence cam 54 is simplymoved further in direction 78 in both instances to accommodate for thesethinner workpieces. Comparing FIGS. 10, 11, and 12, it is easy to seehow clamping down on a thin workpiece simply means roller 56 is movedfurther along surface 68 in direction 78.

An issue that may occur is slight movement of locating pin 6 whileclamped down onto a workpiece. If clamp 2 is locked and air pressure isremoved, if an upward force was exerted on pin 6 it could possibly movethat pin slightly despite staying locked. A repetitive upward forceacting on pin 6 may result in multiple movements of the same which couldknock the clamp out of tolerance. For example, if a 500 pound upwardforce was applied to locating pin 6, it could possibly move despiteroller 56 being wedged against surface 68. A welding gun may exert thisamount of force or even more onto a pin clamp. It is believed thismovement occurs because the components in the clamp stretch just alittle bit. Under a 500 pound force, the movement may be only 0.001inch. But a repetitive force acting on locating pin 6 could multiplythat 0.001 distance many times. Under these conditions roller 56 moves asmall amount but does not roll back into its original clamp positionwhich may cause a creeping effect which may loosen the clamp's grip onthe workpiece. To address this issue, Z-bracket 50 with spring 51 areconfigured to act on sequence cam 54 to push roller 56 back intoposition each time it is inadvertently moved. As shown in FIG. 13, whena force 112 acts upward opposite the clamping direction, roller 56 moveswith respect to surface 68. Tab 52 acts on sequence cam 54 biasing it indirection 78 to push roller 57 back to its original position, as shownin FIG. 14.

An exploded view of these components is shown in FIG. 15. Tab 52 ofbracket 50 is configured to engage edge 114 of sequence cam 54. (Seealso FIG. 5.) As spring 51 acts on tab 53, it acts to keep a bias on tab52 against sequence cam 54. A spring bracket 64 is fitted on cover 12 toreceive bracket 50 and spring 51. Illustratively, bracket 64 includes aspring cavity 116 and slot 118 holds spring 51 and bracket 50,respectively.

A top cross-sectional view of clamp 2 is shown in FIG. 16. This viewshows the relative positioning of bracket 50, spring 51 and sequence cam54. As shown, spring 51 biases tab 53 which causes tab 52 to act onsequence cam 54 biasing the same towards lock bracket 46. This helpskeep roller 56 properly under lock bracket 46.

Front elevational and side cross-sectional views of clamp 2 are shown inFIGS. 17a and b . These views, and particularly the cross-sectionalview, demonstrate how piston rod 60 is attached to a piston 120 insideactuator 16. Another portion of piston rod 122 extends from piston 120partially exterior of actuator 16 and includes a nut 124 attached to theend thereof. Illustratively, nut 124 may be a target for a proximityswitch to detect when the clamp is closed. The surface of 124 may bereflective so that when a beam of light hits it when in a certainlocation, the switch knows the clamp has achieved a certain condition(such as closed). The upper portion of piston rod 60 is coupled tosequence cam 54 via rod 44. In this illustrative embodiment, roller 57is shown within cam slot 74. Illustratively, additional rollers 126 alsosupport rod 44. Roller 57 is configured to transmit force while rollers126 carry side load forces generated by cam slot 74. This has the affectof keeping the piston rod 60 centered.

FIGS. 18 through 21 show additional views of embodiments of the presentinvention, a pin clamp 2 having a housing 4 and a locating pin 6 havinga finger 10. The locating pin 6 again extends through collar 8 attachedto housing 4 using fasteners 25. A cover 12 is again removably attachedto housing 4 using fasteners 14 (not shown), thereby allowing access tothe internal components of clamp 2 as needed. On the opposite side ofhousing 4, a cover plate 40 is again removably attached to housing 4using fasteners 42, also allowing access to the internal components ofclamp 2 as needed. The pin clamp 2 in FIGS. 18 through 21 is againactuated using pneumatic actuator 16 having a piston rod 122 and nut124. Pin clamp mounting holes 128 are provided for mounting the pinclamp 2 to a given support structure (not shown).

Turning now to FIGS. 22 and 23, isometric cutaway views show anadditional embodiment of the present invention compared with a previousembodiment of the present invention. In particular, FIG. 22 shows a pinclamp 2 having a housing 4 and a locating pin 6 with a finger 10 beingactuated using a pneumatic actuator 16, whereas FIG. 23 shows a pinclamp 2 again having a housing 4 and a locating pin 6 with a finger 10but being actuated using an exterior driving linkage 150 that slidesback and forth in directions 82 and 84 using a bearing plate 152. Bothembodiments are again provided with a cavity 18 within the housing 4, inwhich the sequence cam 54 interacts with the locating pin 6 and finger10 through the cam slot 72, drive rod dowel 70, and drive rod 28 in thesame manner as previous embodiments. A Z-bracket 50 again interacts withthe housing 4, cover 12 retained by fasteners 14, and sequence cam 54 tobias sequence cam 54 in direction 78. Collar 8 retained by fasteners 25again guides locating pin 6.

The exterior driving linkage 150 shown in FIG. 23 takes the place of thepiston rod 60 and rod 44 shown in FIG. 22, so that in FIG. 23 dowel pin154 passes through bearing plate 152 and interacts with the cam slot 74of the sequence cam 54 through the cam roller 57 in the same way thatpiston rod 60, rod 44, and cam roller 57 interact with the cam slot 74in previous embodiments. In this way, force applied to boss 170 ofbearing plate in directions 82 and 84 operates the locating pin 6 andfinger 10 of the pin clamp 2 shown in FIG. 23 in the same way that forceapplied to piston rod 60 in directions 82 and 84 by piston rod 122connected to piston 120 of pneumatic actuator 16 operates the locatingpin 6 and finger 10 of the pin clamp 2 in FIG. 22. In place of coverplate 40 and fasteners 42, the pin clamp 2 in FIG. 23 is provided with acover plate 156 having a slot 158 and retained by fasteners 160. Boss170 extends through slot 158 of cover plate 156, thereby providing apoint for exterior driving linkage 50 to be connected to and driven byan external mechanism (not shown) such as a linkage or actuator.

In place of the pin clamp mounting holes 128 in the housing 4 of pinclamp 2 shown in FIG. 22, the pin clamp 2 shown in FIG. 23 is providedwith a mounting assembly 164 that is attached to the housing 4 usingretaining fasteners 166. The mounting assembly 164 is provided with amounting bore 168 by which it may be attached to an external structure(not shown). An end cover 162 separates the mounting assembly 164 fromthe internal mechanism of the pin clamp 2 and protects the internalmechanism from contamination.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. A pin clamp for clamping a workpiece, said pinclamp comprising: a housing; a locating pin extending through saidhousing and having a longitudinal axis, said locating pin being sized tobe positioned within an opening of the workpiece; a finger selectivelyradially extendable from and retractable into said locating pin in atransverse direction relative to said longitudinal axis to retain theworkpiece on the locating pin; an exterior driving linkage configured tomove said locating pin in opposite directions along said longitudinalaxis; a sequence bracket attached to said housing; a lock bracketattached to said housing opposite said sequence bracket; and a sequencecam connected with said exterior driving linkage in a manner allowingaxial movement of said exterior driving linkage to be converted intotransverse movement of said sequence cam perpendicular to saidlongitudinal axis, said sequence cam including a ledge configured toride along a top surface of said sequence bracket during a first part ofa clamping sequence, said sequence cam further including an engagementsurface which engages an angled surface of said lock bracket during asecond part of said clamping sequence to lock said locating pin and saidfinger against the workpiece upon retraction of said exterior drivinglinkage.
 2. The pin clamp of claim 1, wherein: said sequence camincludes an internal cam surface formed therein, and further includes adowel pin coupled with said exterior driving linkage and a cam followerassociated with said dowel pin, said cam follower positioned within saidinternal cam surface and interconnecting said exterior driving linkagewith said sequence cam, said cam follower engaging said internal camsurface and moving said sequence cam in said transverse directions uponmovement of said exterior driving linkage.
 3. The pin clamp of claim 2,wherein: said transverse movement of said sequence cam resulting fromsaid cam follower engaging said internal cam surface further causingsaid ledge to disengage from said top surface of said sequence bracketand causing said engagement surface to engage said angled surface ofsaid lock bracket.
 4. The pin clamp of claim 2, wherein said camfollower is a cam roller.
 5. The pin clamp of claim 2, wherein saidexterior driving linkage further comprises a bearing plate that isslidable parallel to said longitudinal axis and that carries said dowelpin perpendicular to said longitudinal axis.
 6. The pin clamp of claim5, wherein said bearing plate further comprises a boss for providing apoint for said exterior driving linkage to be connected to and driven byan external mechanism.
 7. The pin clamp of claim 6, wherein said dowelpin passes through said boss.
 8. The pin clamp of claim 6, wherein saidhousing further comprises a cover plate having a slot, said boss passingthrough said slot in said cover plate.
 9. The pin clamp of claim 1,wherein: said sequence cam locks said locating pin and said fingeragainst the workpiece upon and after removal of power from said exteriordriving linkage.
 10. The pin clamp of claim 9, wherein: said pin clampis configured to clamp onto different workpieces having a differentthickness.
 11. The pin clamp of claim 10, wherein: said differentworkpieces have a difference in thickness of up to approximately 1.0 mm.12. The pin clamp of claim 1, wherein: said sequence cam includes aroller defining said engagement surface.
 13. The pin clamp of claim 12,wherein said angled surface of lock bracket is positioned at an acuteangle of between approximately 0° to 10° relative to said transversemovement of said sequence cam, and wherein said roller locks under saidangled surface.
 14. The pin clamp of claim 13, wherein said acute angleis between 5° to 10°.
 15. The pin clamp of claim 13, wherein said angledsurface is one of flat and curved.
 16. The pin clamp of claim 1, furthercomprising a mounting assembly having a mounting bore attached to saidhousing.